Lowdeck System

The next generation in timber sub-frames

A solution for rooftops, balconies, waterproof membranes & low height decks.

Introducing LOWDECK – a new range of engineered timber bearers and joists specially designed for use in low height decking. Treated to H4 Hazard rating making it suitable for ground contact use, LOWDECK uses Koppers Micro® Timber Treatment Technology, to protect from fungal decay, termites & insect attack and supported by a treatment warranty of 50 years. Engineered GL8 structural grade strength (roughly F7 equivalent) and double sealed with a high-quality oil-based primer to provide further protection.

Affordable, Versatile, and Easy-to-Use

The Perfect Match for Millboard Decking

Lowdeck System provides an affordable and user-friendly alternative to steel or aluminum decking solutions. It is specifically designed to complement Millboard decking, making it an ideal combination. Unlike other decking products, Millboard does not require minimum clearance or ventilation, making it a seamless match for the Lowdeck System. Additionally, Lowdeck System offers a smart upgrade from regular H3 Treated pine joists, enhancing the quality of your building projects. For ultra-low decks installed over concrete slabs or waterproof membranes, you can utilize plastic packers or opt for Millboard’s Joist Cradles and Self-Leveling Pedestals. These accessories help level out the deck, elevate the joists or bearers, and promote proper drainage, ultimately improving the deck’s service life and performance.

Overcoming Height and Durability Constraints

Why is LOWDECK needed?

Regular H3 Treated pine bearers and joists are bread and butter for deck sub-structures – But the H3 Hazard Rating is intended for above ground use only and assumes sufficient clearance and design to allow for ventilation. This is to minimise the risk of the frame rotting out and the decking above it cupping and warping etc. Below 400mm height issues with ventilation and moisture can impact the service life and appearance of the deck. Lower again under 150mm H3 timber should not be used. “Framing timbers on the ground or lower than 150 mm should be termite resistant and in-ground durability Class 1 or treated to H4 or better.” (Source: Technical Design Guide – FWPA – Domestic Timber Deck Design) It’s becoming more common for finished height thresholds to be very low – with many outdoor patio and slab areas on new builds, concrete balconys and rooftops leaving little height for the decking & substructure. For these areas LOWDECK provides the solution.